The present invention relates to a piston cooling system for an internal combustion engine.
It is known to deploy spray nozzles for spraying a coolant against the undersides of the pistons of an internal combustion engine. Lubricating oil drawn from a pressurized oil circuit is used as the coolant. In one conventional arrangement, the spray nozzle is formed as a bent pipe mounted to a console or bracket which, in turn, is bolt mounted to an inner surface of the crankcase housing such that coolant is propelled through the bent pipe against the underside of a piston.
A disadvantage of the just described conventional arrangement is that the bent pipe is mounted to the console by a solder weld. The console itself is secured by a bolt to the inner surface of the crankcase housing. Due to the difficulty of accessing the area where the spray nozzle is installed onto the crankcase housing, this installation work can only be accomplished by hand and is for that reason very costly while, moreover, the solder welding of the console and the bent pipe of the spray nozzle add to the cost.
The present invention provides a piston cooling system which permits the spray nozzles to be fabricated as compact pieces formed by a lathe process such that the time consuming work activities such as the bending of pipe, solder welding, and other activities can be dispensed with. Additionally, the spray nozzles of the piston cooling system of the present invention can be easily installed into their operating orientations within the longitudinal bores which receive them by means of a work tool such as, for example, a robot.
Due to the ability to install the spray nozzles into their operating orientations, the orientations of the spray patterns of these spray nozzles are clearly defined and damage to the internal combustion engine due to deficient cooling of its pistons can be prevented. In contrast, the spraying precision of a conventional spray nozzle formed by a bent pipe cannot be guaranteed. The manual installation requirements of such conventional spray nozzles are not consistent with the mass production of items such as vehicle internal combustion engines.
The spray nozzles of the present invention, which are pieces formed by a lathe process, can be fabricated in a pure, fully automatic manner by machining, which is a cost favorable process, and can accordingly have uniform quality.